In a principal aspect, the present invention relates to a coupler device which may be utilized in restricted access areas by attachment to a grease fitting or “zerk” fitting.
When servicing a vehicle such as an automobile or truck, it is typically necessary to couple a source of grease to the grease fittings, often termed zerk fittings, located at strategic positions on the vehicle, for the injection of grease or lubricating materials. Often, the zerk fittings are positioned in restricted spaces. Access to the fittings in order to pump grease or lubricating material into and through the fittings is therefore difficult. As a result, there has developed the need for a mechanism or device for attachment or coupling to a grease fitting from the side of the grease fitting rather than from the top of the fitting.
One known type of device comprises a molded urethane coupler having an open slot at one end. The zerk fitting may then be inserted into the open slot formed in the coupler and retained by a rib molded in the coupler so that grease or lubricating material may be pumped via a tube through the coupler into the grease fitting. The molded elastic retaining rib comprises a detent mechanism which frictionally retains the fitting engaged with the coupler device.
Such a prior art device or coupler is useful and does improve the ability to access zerk fittings located in restricted spaces. However, because such a coupler must be used with fittings having different sizes and shapes, the frictional retention rib does not always successfully insure retention of engagement of the coupler with the fitting, and in some circumstances, the frictional fitting is too difficult to permit engagement with the fitting.
U.S. Pat. No. 6,035,969 entitled “Grease Gun Extension Coupling Device” granted Mar. 14, 2000 discloses another device for attachment to a zerk fitting. An outer tube fits over the neck of the zerk fitting and a rotatable inner tube facilitates locking of the outer tube and the assembly to the fitting while simultaneously serving as a conduit for the grease flow into the fitting. Such a device requires elongate concentric tubes and may not be useful in some restricted areas.
Thus, there has developed a need for an improved mechanism or device for coupling a source of lubricating material from a tube, particularly a flexible tube, to a zerk fitting positioned in a restricted space.